Atomizer for liquid fuels



Oct. 14, 1941. E. TAYLOR ATOMIZER FOR LI UID FUELS Filed May 24, 1939INVENTOR Z22 1)? zllv/ar Y l'l' III-[ ll ATTORNEYS a layer.

Patented Oct. 14, 1941 2,259,011 ATOMIZER FOR LIQUID FUELS V EdwinTaylor, Brooklyn, N. Y., assignor of twofifths to William F. Doyle,Summit, N. J.

- Application May 24, 1939, Serial No. 275,463

6 Claims.

This invention relates to the atomization of liquid fuels, and inparticular to an improved method and apparatus adapted to atomize withincreased efliciencies a liquid combustible material in the presence ofa combustion-supporting gas. The improved apparatus of the invention isof the type which includes an atomizing head in which is incorporated aconical block at the peripheral edge of which the major portion of theatomization occurs.

It is an object of my invention to provide a method and means-foreffecting'an increased degree of atomization of a liquid fuel, therebyincreasing the efficiency of combustion without the use of increasedamounts of air or other combustion-supporting medium, or a substantiallyincreased pressure on the fuel or air lines, and concurrently therewithto supply a portion of the air to the zone of combustion in'amanner-which permits increased efliciencies in combustion.

It is also an object of the present invention in one of its preferredembodiments to provide a method and an improved apparatus for sprayingradially outwardly a highly atomized mixtureof a liquid fuel and anoxygen-containing gas ina circular disc-like sheet substantiallyparallel to a contact surface positioned opposite the base of the coneand perpendicular to'the axis of the atomizer. Myinvention in accordancewith this embodiment is particularly adapted for 'use. in injecting ahighly atomized liquid fuel and combustion-supporting medium between theparallel, dome-shaped, or conical contact surfaces of a generator forproducing a heat-conveying pressure fluid medium as described andclaimed in my co-pending application for Letters'Patent,

Serial No, 275,462, filed of even date herewith.

It is a further object of my invention to provide a method and means forproducing a'hollow globular-shaped body of atomized fuel, or, in theevent that the fuel is being burned in a suitable open space orfire-box, a globular-shaped flame.

It has previously been proposed to atomizea liquid fuel by passing itthrough an atomizer having an. outer cylindrical casing, one edge ofwhich is beveled to serve as a seat for an adjustably supportedconically shaped member which extends into the cylindrical casing. Insuch a device the oil or other liquid fuel is passed outwardly over thesurface of the cone in a thin A stream of air, usually through anannular space, is directed'under pressure onto the surface of the cone.The air and oilpass simultaneously through the narrow space between thebeveled cylindrical casing and the conical head where atomization of thefuel begins, and, upon reaching the sharp edged periphery of the cone,produce the major part of the atomization.

I have now found that for a given amount of air at a specifiedpressuresupplied to the atomizer, an increased degree of atomization, togetherwith numerous other advantages hereinafter more fully discussed, may beachieved in the just described conical type of fuel-atomizing head bydirecting a supplemental current of combustion-supporting medium to theperiphery of the cone by passing it radially outwardly from and in adirection substantially perpendicular to the axis of the cone. This mayconveniently be accomplished by providing a substantially flat surfacespaced a short distance from the base of the cone and fixed in aparallel position with respect thereto, whose area is at least as greatas that of the base of the cone; As hereinafter more-fully explained,the area of this baffle plate may be greatly in excess of that of thebase of the cone, depending on the type of atomized fuel injection whichis desired. A plurality of concentrically spaced tubular apertures,extending through the conical head of the atomizer, will then'beeffective to introduce air into the area adjacent the base of theconical block, and the referred to flat surface will divert the airstreams and cause them to pass in a spreading sheet radially outwardlypast the periphery of the cone. As an alternative, the supplementary airmay be introduced through the flat plate opposite the cone. In this casethe solid base of the cone will serve to divert the supplementary airsupply radially outwardly to the periphery of the cone. A furtheralternative methodv of introducing supplementary air below the surfaceof the conical block involves oneor more tubular openings disposedlongitudinally within the tube or cylinder to which the conical head isattached, and which pass through the cone. Such arrangements are,however, not as convenient as the structure to be described in detailbelow, since they involve a separate introduction means for thesupplementary air. I

An outstanding advantage of the fuel-atomizing device of the presentinvention is the fact that the increased atomization produced does notinvolve the use of increased quantities of combustion-supporting mediumor its use under increased pressures. To produce an equivalent degree ofatomization without the introduction of the referred to supplementaryair supply would necessitate the use of air in the atomizer havingconsiderably augmented pressure over that to be found outside theatomizer or at the periphery of the conical surface. My inventionpermits the use of a very small diiferen'tial in the pressure betweenthe inside and outside of the atomizer.

A further advantage of an atomizing device of the present inventionresides in the fact that it may be interchangeably employed for themixing and injection of a gaseous fuel and a combustionsupportingmedium, should necessity demand a shift of fuel from a liquid to a gas.Under such circumstances, only a very small proportion of:

the gaseous fuel will pass through the ports extending through theconical head of the atomizer, due to the fact that substantially all ofthe mixing will occur in the spraying orifice adjacent the periphery ofthe conical surface.

The improved atomizing process and apparatus of my invention will now bedescribed with ref erence to the appended drawing illustrating twoembodiments of my invention.

In the accompanying drawing, wherein like reference numerals designatelike parts:

Figure 1 is a vertical axial section of a fuelatomizing head fordelivering an atomizedmixture in a disc-like sheet in accordance withthe present invention, parts being broken away and other parts shown inelevation.

Figure 2 is a transverse section on the line 2-2 of Figure 1.

Figure 3 is a similar transverse section taken along the line 33 ofFigure 1.

Figure 4 is afragmental axial section of a fuelatomizing head fordelivering a hollow globular flame in accordance with an alternativeembodiment.

In the atomizing means illustrated in Figure 1, a cylindrical housing 5is partially closed at one end by a-closure plug 5 or by an extension ofthe housing. A tubular housing 1- of substantially smaller diameterdisposed within and coaxially aligned with the outer housingfi is heldin place at one end by the closure member 6 and-is further supported byspider supports 8. Axially movable within the tubular housing I isa-fluted rod 01' tubeSl, having an extension H3 which is adjustable bymeans of a threaded connection it in the closure member 6 or in aseparate plug member [2 located therein. The tubular member I isprovided at its outer end with a beveled annular seat I3; adapted toform an oil-tight closure with the outer surface of aconical block M,which depends from the bottomof the fluted member 9. It will be apparentthat by an extension of the central mechanism an annular opening of anydesired Width can be produced between the beveled seat !3 and thesurface of the conical block for controlling the flow of oil fromannular distribution chamber 55 outwardly over thesurface of said cone.The closure member 6 is arranged to produce an annular space it) intowhich leads a liquid fuel delivery pipe H and which communicates withthe grooves l8 inthe fluted member 9. The outer housing 5. is alsobeveled at the end opposite the closure member to form with the conicalblock a circular spray"- ing aperture adjacent the periphery thereof andexteriorly of the inner cylindrical housing 17. The two housings arewith advantage so arranged that when housing 1 comes into engagementwith the surface of the cone, there is a small clearance between thecone and the outer wall 5. When the position of the conical block ischanged, therefore, the outer aperture, will be larger than the innerfuel aperture. An air inlet pipe I9 leads to the annular air chamber 23,defined by the concentric cylinders 5 and I. A plurality of tubularports 2| extends from the air chamber 20 through the conical head,either vertically or at an outwardly inclined angle. These ports extendinwardly into chamber 20, a distance sufficient to prevent oil flowingover the conical surface from passing therethrough. The base of the conein the atomizing head is spaced from a flat plate 22 of a considerablylarger area than the base of the conical block. The air passing throughports 21 is diverted radially outwardly by this plate away from the axisof the cone, and delivered to the periphery of the base of the cone toproduce further atomization. A portion of the air so diverted forms alayer of combustion-supporting medium between the atomized mixture andthe surface of plate 22, and serves as a cushion to prevent the atomizedmixture immediately contacting the surface.

In operation, oil fed through pipe i7 enters annular chamber l6, passingtherefrom through grooves [8 to the annular space l5, said spaceeffecting an even distribution of the oil flowing radially outwardlyover the conical surface of the atomizing block. The oil is dischargedfrom said annular space at a rate regulated by the distance between theblock and the beveled seat [3. Air introduced through pipe i9 passesthrough chamber 20 and outwardly through the passage created by theconical block and the beveled surface extending around the edge of thehousing 5. The initial but limited break-up of the oil into globulesoccurs in this annular passage. Arriving at the sharp edge of theconical block, the air serves to produce a high degree of atomization ofthe oil as it arrives at the same sharp edge from which the atomizedmixture is discharged. A portion of the air dependent on the size andnumber of the ports 2! passes directly therethrough, and is divertedradially outwardly past the surface of the base of the conical block bythe surface 22. Arriving at the periphery of the cone from the oppositeside from the air passing through the passage 23, a marked increase inthe degree of atomization of the oil is produced when compared to thatresulting when no such opposing supplementary air stream is provided.The number and diameter of tubular ports 2| may be varied. In generalfour or more are recommended, having diameters such that the totalcross-sectional area is appropriate to pass approximately to of the airsupplied to chamber 20'. The conical block as here shown has an apexangle of The primary requirement with respect to the delivery of therelatively thin sheet of combustible liquid through annular space 23 isthat it be passed therethrough in a path of substantially conicalconfiguration. It will be understood that the flow of the liquid in aconical configuration may not only be effected by passing it over thesurface of a conical blocl: of the type illustrated, but also over theouter surface of ahollow cone-shaped member. In the latter case, tubularports are fixed in the cone-shaped surface in a manner suitable toconduct a portion of the air through the oil traveling over the surfaceand out of direct contact therewith.

The fluted cylindrical member 9, movable longitudinally of the cylinder1, may be replaced by a solid fluted rod, or by a rod having internaltubular passages, but for practical reasons a fluted member of the typeillustrated is preferred. .Ayfurther alternative structure embodies arod passing through the center of cylinder 1, having a smaller diameterthan said cylinder, thus providing an annular delivery chamber for thecombustible liquid. Such an arrangement, however, introduces a problemin the alignment of the cone; and the necessary bearings adjacent thebottom of cylinder I to accomplish such alignment, introduce anunnecessary practical dimculty. r

An atomizing. mechanism such as that described is effective in sprayingan atomized fuelair mixture in a direction substantially parallel to asingle fiat plate or between two substantially parallel closely spacedflat plates. Conical angles slightly'greater than 120 are permissible,but any angle substantially greater than this value is not recommendedbecause the beveled annular opening, whose angle iscorrespondingly'less, does not permit a satisfactory degree of,atomization. Angles less than 120, specifically between 100 and 120,result in the production of an atomized sheet of fuel and airprogressively removed from a plane perpendicular to the axis of thecone. A conical angle substantially less than 120, therefore, is not aseifective for use between two flat parallel surfaces, but may be usedwith particular advantage to inject a fuel-air mixture between parallelsurfaces having a conical or dome-like configuration. In such anarrangement, wherein the conical angle or dome-shaped arrangementpossesses a wide angle, the atomizer is positioned at the apex of thecone or dome-shaped structure, and is effective in spraying the mixtureradially outwardly between the plates.

An important result of the novel method herein described for introducingsupplementary air when used in combination with a method of atomizinginvolving the use of a conical head as described, is that the atomizedmixture of air and oil is propagated between two layers of thecombustion-supporting medium which serve to cushion the mixture andprevent it from coming directly into contact with the surfaces of theplates at a point immediately adjacent the atomizer. Such a result is ofparticular advantage with the fuel-air mixture is being combustedbetween closely spaced catalytic surfaces having the configuration ofthe plates described herein with reference to Figure 1.

As indicated above a conical head having an angle between 100 and 120tends to discharge an atomized mixture having a somewhat conicalconfiguration, and suitable for injection between closely spacedcombustion surfaces. In accordance with a further embodiment of myinvention now to be described, a hollow globular injection, or flame, ifthe atomized mixture is being burned in an open fire-box, may readily beproduced by employing a conical member in the atomizer having an angleranging from 90 to about 100, and with particular advantage 90. Theimproved atomization of my invention may be effected in such a case byproviding a flat plate, having substantially the same diameter as thebase of the cone, opposed to and spaced from the bottom of said cone. Anapparatus in accordance with this embodiment is illustrated in Figure 4of the drawing, wherein plate 24, held in position by bolt or extensionmember 25, serves to divert the air passing through ports 2| in adirection away from the axis of the conical block l4. Such an apparatushas the advantage that it provides a globular-shaped injection of fuelwhich possesses an increased degree of atomization, as a result of whichmore eilicient combustion occurs even when the fuel is being burned inan open fire box.

I claim:

'- '1'. The metho of obtaining improved atomizabetween thecombustion-supporting medium and the liquid, an additional supply ofcombustionsupporting medium through said path of conical configurationand out of direct contact therewith, divertingsaidadditional supply ofcombustion-supporting medium radially away from the axis of said conicalconfiguration in a plane substantially perpendicular to said axis, anddischarging the mixture of combustible material andcombustion-supporting medium into the path of said diverted-stream ofcombustion-supporting medium.

2. In a fuel atomizing device, means for passing a relatively thin sheetof combustible liquid outwardly over a conical surface, having an apexangle not less than about means for delivering a combustion-supportingmedium adjacent the sheet of combustible liquid, means for directing thecombustible liquid and thecombustion-supporting medium in a confinedstream to the periphery of said conical surface, a plurality of tubularports extending through said conical surface for discharging a portionof said combustion-supporting medium below the conical surface, saidports being extended above the conical surface, and means for divertingthe thus discharged portion of combustion-supporting medium radiallyoutwardly past the periphery of the conical surface whereby improvedatomization of the liquid combustible material is effected.

3. In a fuel atomizing device spaced from a fiat surface which isperpendicular to the axis of the device, means for passing a relativelythin sheet of combustible material outwardly over a conical surface,having an apex angle not less than about 90, means for delivering acombustion-supporting medium adjacent the thin sheet of combustibleliquid, means for directing the combustible liquid and thecombustion-supporting medium in a confined stream to the periphery ofsaid conical surface, means'for discharging a part of the saidcombustion-supporting medium from adjacent the combustible liquidthrough the conical surface and the liquid flowing thereover and intothe region below the conical surface, whereby the thus dischargedportion is caused to flow radially away from the axis of the conicalsurface past the periphery to effect increased atomization of the liquidcombustible material.

4. In a fuel atomizing device, an outer cylindrical wall, an innercylindrical wall coaxially aligned therewith to form an outer annularchamber for a combustion-supporting medium, a conical block having anapex angle not less than about 90", extending into and movably spacedfrom the delivery end of each of said cylindrical walls to form with thebeveled edge of the inner wall an annular passage for supplying acombustible liquid to the surface of the conical block, and to form withthe beveled edge of the outer cylindrical wall an annular sprayingaperture for the combustible liquid and the combustion-supportingmedium, and a plurality of tubes passing through said conical block andextending into said'outer annular chamber for discharging a portion ofthe combustion-supporting: medium below the base of the conical blockand adjacent a flat surface spaced from said base.

5. In a fuel atomizing device, an outer cylindrical wall, an innercylindrical wall coaxially aligned therewith to form an outer annularchamber for a combustion-supporting medium, a conical block having anapex angle approximating 120 extending into and movablyvspaced and toform with the beveled edge of the outer cylindrical wall an annularspraying aperture for the combustible liquid and thecombustion-supporting medium, and a plurality of tubes passing throughsaid conical block and extending into said outer annular chamber fordischarging a portion of the combustion-supporting medium below the baseof the conical block and adjacent a fiat surface spaced from said base.

6. In a fuel atomizing device, an outer cylindrical wall, an innercylindrical wall coaxially aligned therewith to form an outer annularchamber for a combustion-supporting medium, a conical block having anapex angle approximating 90 extending into and movably spaced from thedelivery end of each of said cylindrical Walls to form with the bevelededge of the inner wall an annular passage for supplying a combustibleliquidrto the surface of the conical block, and to form with the bevelededge of the outer cylindrical wall an annular spraying aperture for thecombustible liquid and the combustion-supporting medium, a substantiallyflat circular plate having a diameter approximately equal. to thediameter of the base of conical block depending from said base, .and aplurality of tubes passing through said conical block and extending.into saidlouter annular chamber for discharging a portion of thecombustion-supporting medium between the base of the conical block andsaid circular plate.

EDWIN TAYLOR.

